This section is intended to introduce the reader to various aspects of art, which may be related to various aspects of the present disclosure that are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
Sensors in digital cameras have a limited dynamic range that hinder to obtain all the details in scenes with difficult illumination. Therefore, when taking a photo, the user is faced with the choice of either rendering details in shadow areas and overexposing the highlights, or exposing for highlights but losing details in darker zones. In order to overcome this issue, HDR (which stands for “High-Dynamic-Range”) imaging techniques can be used, which aim is to reproduce a greater dynamic range of luminosity than possible using standard digital imaging or photographic (i.e. classical sensors in the sense that these sensors have a limited dynamic range). In order to achieve this result, one technique relies on the taking of multiple acquisitions of a same scene but at different exposure. Such technique is called a bracketing technique. Once these multiple images are obtained, they are aligned (or registered) and merged (or fused) into one single HDR image. The image registration/aligning process is the process of aligning (from a spatial point of view) the images of a same scene in order to compensate for camera movement between the shots performed during the take of multiple acquisitions. Indeed, this aligning process is necessary to avoid the obtaining of a blurry HDR image. However, this is a very costly operation both computationally and memory-wise.
The present disclosure aims at speeding up the aligning process when obtaining/generating an HDR image, as well as improving the quality of the obtained HDR image in some embodiments of the disclosure.
It should be noted that the present disclosure can also be used in order to generate an HDR image from a 3D camera.